My Period 9 Practice Padlet by Mitchell Graham https://padlet.com/203745/a0itvmqt1gk7 Made with fresh s w a g. en-us 2016-11-10 18:14:46 UTC 2025-04-18 16:18:52 UTC hello@padlet.com 400-350 BC:                 The Atomic Theory 215082 https://padlet.com/203745/a0itvmqt1gk7/wish/136839338 Democritus developed the Atomic Theory claiming that matter is mad up of tiny particles known as atoms. Aristotle opposed this theory stating that matter was made up of the four elements: Earth, Fire, Water, and Air.

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]]> 2016-11-10 18:28:07 UTC https://padlet.com/203745/a0itvmqt1gk7/wish/136839338 1803: Dalton Model 203745 https://padlet.com/203745/a0itvmqt1gk7/wish/136839871 Chemist John Dalton performed experiments that eventually helped lead to the acceptance of atoms. He concluded that everything is made out of atoms, and that they were indivisible and indestructible. He also concluded that atoms of the same element were alike, and atoms of different elements were different. Finally, he concluded that the combination of two or more atoms resulted in a compound.
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]]> 2016-11-10 18:29:15 UTC https://padlet.com/203745/a0itvmqt1gk7/wish/136839871 1913: Neils Bohr 215082 https://padlet.com/203745/a0itvmqt1gk7/wish/137060270 Found that electrons move around the nucleus at successfully large orbits. Much like the planet orbits. the orbits represent energy levels. During this time, he came up with the Bohr atomic model showing his idea of an atom and how it works.
https://goo.gl/JP4kGo]]> 2016-11-11 17:38:22 UTC https://padlet.com/203745/a0itvmqt1gk7/wish/137060270 1911: Rutherford Model 203745 https://padlet.com/203745/a0itvmqt1gk7/wish/137065321 Rutherford conducted an experiment using a piece of gold foil and a gun that he made that shot alpha particles. Rutherford's original idea was based off of the Thomson Model of an atom, which included the electrons mixed throughout the protons. Rutherford hypothesized that since all the particles in an atom were spaced out, the particles from the alpha gun would pass right through the gold foil. However, sometimes the alpha particles would bounce off of the gold foil, which is the complete opposite of what Rutherford thought would happen. After Rutherford received this same result several times, he concluded that the alpha particles must be hitting something with the same charge. It was from this experiment that Rutherford concluded that atoms had a nucleus made out of protons, with the electrons surround it.
https://goo.gl/LqbI3P]]> 2016-11-11 18:02:44 UTC https://padlet.com/203745/a0itvmqt1gk7/wish/137065321 1897: Thomson's Plum Pudding Model 203745 https://padlet.com/203745/a0itvmqt1gk7/wish/137067440 In 1897, J.J. Thomson, an english scientist, had reason to believe that atoms were made out of even smaller particles. J.J.'s ideas of these smaller particles came about when he conducted an experiment on a cathode tube. J.J. analyzed and studied the passage of an electric current through a gas, or the passage of an electric current through the cathode tube. J.J. realized that when the current passed through the gas, it gave off negatively charged particles. Since the atoms of the gas weren't charged, Thomson was surprised by this observation. It was from this realization that J.J. concluded that the negatively charged particles had come from within the atoms, and that an atom was therefore divisible. He also reasoned that since the atom was giving off negatively charged particles, there must also be positively charged particles somewhere in the atom. Unfortunately, J.J. never found these particles and settled upon a new model of an atom. He called this model, The Plum Pudding Model, since he hypothesized that the electrons were spread all around an atom, with the protons surrounding them. 

]]> 2016-11-11 18:12:06 UTC https://padlet.com/203745/a0itvmqt1gk7/wish/137067440 1900: The Quantum Theory 215082 https://padlet.com/203745/a0itvmqt1gk7/wish/137068532 The atomic module of today is wade from the atomic Wave Quantum Mechanics. Proposed by this theory, electrons do not move in any certain path. In other words, Bohr was wrong. It is impossible to find the exact location of an electron at any time. Atom "clouds", or "orbitals" are where electrons are generally found at. The amount of energy the atom has determines the general location of electrons.
https://goo.gl/YnztkZ]]> 2016-11-11 18:17:18 UTC https://padlet.com/203745/a0itvmqt1gk7/wish/137068532